import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int ret=0;
        String str=sc.nextLine();
        char[] ch=new char[str.length()];
        for(int i=0;i<str.length()/2;i++){
            if(ch[i]!=ch[str.length()-1-i]){
                ret=1;
            }
        }
        if(ret==1){
            System.out.println("NO");
        }else{
            System.out.println("YES");
        }
    }
    public static void main4(String[] args) {
        Scanner sc=new Scanner(System.in);
        int nn=sc.nextInt();
        int kk=sc.nextInt();
        int[] arr=new int[nn];
        int num=0;
        for(int i=0;i<nn;i++){
            arr[i]=sc.nextInt();
        }
        for(int i=0;i<nn;i++){
            if(arr[i]+kk<=5){
                num++;
            }
        }
        System.out.println(num/3);
    }
    public static void main3(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int cnt=0;
        while(n!=1){
            System.out.print(n+" ");
            if(n%2==0){
                n/=2;
            }else{
                n=3*n+1;
            }
            cnt++;
        }
        System.out.println(1);
        cnt++;
        System.out.println(cnt);
    }
    public static void main2(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        func(n);
    }
    public static void func(int n){
        int sum=0;
        int res=-1;
        for(int i=0;i<n;i++){
            res+=2;
            sum+=res;
        }
        System.out.println(res);
        System.out.println(sum);
    }
    //逆序输出字符串
    public static void main1(String[] args) {
        Scanner sc=new Scanner(System.in);
        String str=sc.nextLine();
        char[] arr=new char[str.length()];
        for(int i=0;i<str.length();i++){
            arr[i]=str.charAt(str.length()-i-1);
        }
        for(int i=0;i<str.length();i++){
            if(i<str.length()-1){
                System.out.print(arr[i]+"-");
            }else {
                System.out.print(arr[i]);
            }
        }
    }
}